Electrophoretic display and manufacturing method

ABSTRACT

The present invention provides an electrophoretic display in which an insulating liquid is uniformly provided to the divided microspaces each corresponding to one pixel and display characteristics uniform over the display surface are actualized. The present invention includes a transparent first substrate  1  and a transparent second substrate  2  arranged with a predetermined gap therebetween, charged particles  6  dispersed in an insulating liquid  5  provided to the gap, and a first electrode  3  and a second electrode  4  arranged on either of the first substrate  1  and the second substrate  2,  wherein liquid-repellency parts  8  and repellency-lowered parts  9  are arranged on the surface of the first substrate  1  and the surface of the second substrate  2,  and the insulating liquid  5  is provided to the repellency-lowered parts on the surface of the first substrate  1  and the surface of the second substrate  2.

BACKGROUND OF THE INVENTION

The present invention relates to a display, particularly, anelectrophoretic display in which display is effected by movement ofcharged particles in a liquid.

As a nonluminescent display, an electrophoretic display has been knownwhich takes advantage of the electrophoretic phenomenon. Theelectrophoretic phenomenon is the one in which when an external electricfield is applied to charged particles in a liquid, the charged particlesmigrate according to the charge polarity and the direction of theelectric filed. As a conventional electrophoretic display, for example,an electrophoretic display has been known in which a colored insulatingliquid is used (JP-A-2001-343672). The electrophoretic display disclosedin JP-A-2001-343672 has a structure in which one electrode and the otherelectrode are opposed to each other with a predetermined separationtherebetween, and a liquid is contained in the gap therebetween. When avoltage is applied between the two electrodes, the charged particles arerespectively attracted to one of the electrodes according to the chargepolarities thereof. In this case, a colored insulating liquid is used sothat an observer views either the color of the charged particles or thecolor of the liquid. Accordingly, an image is displayed by controllingthe voltage applied between both electrodes.

As a conventional electrophoretic device in which no colored insulatingliquid is used is disclosed, for example, in JP-A-11-202804. InJP-A-11-202804, the device has a structure in which one electrode issmall in area and the other electrode is large in area. When a voltageis applied between both electrodes, charged particles are respectivelyattracted to one of the electrodes according to the charge polarities ofthe particles. In this case, an observer views the color of the chargedparticles and the color of either of the electrodes; more specifically,owing to the electrode area difference, the observer mainly views thecolor of the charged particles when the charged particles are attractedonto the electrode with a large area, while the observer views mainlythe color of the electrode when the charged particles are attracted ontothe electrode with a small area. Accordingly, by controlling the appliedvoltage, an image can be displayed.

The insulating liquid in the above described conventionalelectrophoretic devices is placed the respective compartments separatedby partition walls; the partition walls serve to maintain the gapbetween the upper and lower substrates and limit the migration range ofthe charged particles respectively within the compartments made up ofthe partition walls to prevent the diffusion of the charged particles.

In the above described prior art electrophoretic displays, a largenumber of unit pixels of microspaces formed beforehand by division withthe aid of the partition walls are provided with an insulating liquid,and the thus prepared pixels are arranged in a form of matrix to form atwo-dimensional display area; however, such a configuration preventsuniform distribution of the insulating liquid over the microspaces, andaccordingly it is difficult to achieve a uniform display characteristicover the surface of the display area. An object of the present inventionis to provide an electrophoretic display in which the microspaces formedby division into pixels are uniformly provided with an insulating liquidso that a uniform display characteristic is achieved within the displaysurface.

SUMMARY OF THE INVENTION

For the purpose of achieving the above described object, in the presentinvention, transparent first and second substrates are arranged with apredetermined gap therebetween, an insulating liquid is provided in thegap, charged particles are dispersed in the above described insulatingliquid, a first electrode and a second electrode are each arranged oneither of the above described first substrate and the above describedsecond substrate, liquid-repellency parts and repellency-lowered partsare provided on the surface of each of the above described firstsubstrate and the above described second substrate, the insulatingliquid is provided on the repellency-lowered parts of each of the abovedescribed first substrate and the above described second substrate, andaccordingly the above described insulating liquid is uniformlydistributed over the whole pixels.

Additionally, the present invention can take the followingconfiguration.

-   (1) The patterning form of the liquid-repellency parts and the    repellency-lowered parts on the surface of the above described first    substrate and the corresponding pattering form of the above    described second substrate are made identical with each other.-   (2) Liquid-repellency parts and repellency-lowered parts are    arranged on either of the above described first substrate surface    and the above described second substrate surface, the other    substrate surface being wholly made liquid-repellent.-   (3) The above described insulating liquid provided on the    repellency-lowered parts of the above described first substrate and    the above described second substrate is provided by handling the    individual pixels separately, or by handling a plurality of pixels    as a group.-   (4) The contact angle between each of the above described    repellency-lowered parts flat in surface and the above described    insulating liquid is made to be smaller than 90 degrees, and uneven    structure is formed on the above described repellency-lowered parts.-   (5) A plurality of posts is arranged on the above described    liquid-repellency parts, and the surface of each of the above    described posts is made to have liquid-repellency against the above    described insulating liquid.-   (6) Spacer members (beads or posts) are arranged to maintain the gap    between the above described first substrate and the above described    second substrate, and the surface of each of the spacer members is    made to have liquid-repellency against the above described    insulating liquid. Additionally, the spacer members are made to be    nearly black.-   (7) Banks higher than the surroundings thereof are arranged on the    parts of the first substrate or the parts of the second substrate,    or the parts of both substrates involved in the boundary parts    between the adjacent compartments of the insulating liquid arranged    on the above described repellency-lowered parts. Furthermore, the    surface of each compartment of the above described insulating liquid    is covered with a transparent resin film.-   (8) A resin is provided to the gaps between the above described    adjacent compartments of the insulating liquid covered with the    above described resin film. The resin provided to the gaps between    the above described adjacent compartments of the insulating liquid    covered with the above described resin film is made to be nearly    black. Additionally, the resin provided to the gaps between the    adjacent compartments of the insulating liquid covered with the    above described resin film is made to have conductivity so as to    double as the above described first electrode.-   (9) The gaps between the compartments of the insulating liquid    covered with the above described resin film and the above described    first substrate and the gaps between the compartments of the    insulating liquid covered with a resin are filled with a transparent    conductive resin so as double as the above described first    electrode.-   (10) Liquid-repellency parts and repellency-lowered parts are    arranged on the above described surface of the second substrate, the    surfaces of the first electrode and the second electrode both    arranged on the above described second substrate, and the surface of    the above described second substrate, and the above described    insulating liquid is provided to the repellency-lowered parts of the    above described second substrate surface; the surface of the    compartments of the insulating liquid are covered with a resin film.-   (11) A transparent conductive resin is provided on the surface of    the above described compartments of the insulating liquid covered    with the above described resin film and in the gaps therebetween.-   (12) Liquid-repellency parts and repellency-lowered parts are    arranged on the surface of the above described second substrate, on    the surfaces of the second electrode arranged on the above described    second substrate, and on the surface of the above described second    substrate, and the above described insulating liquid is provided to    the repellency-lowered parts of the above described second substrate    surface; the surface of the compartments of the above described    insulating liquid are covered with a resin film; a transparent    conductive resin is provided on the surface of the compartments of    the above described insulating liquid each covered with the above    described resin and in the gaps therebetween so as to also be the    first electrode; moreover, a transparent nonconductive resin layer    on the surface of the above described conductive resin.-   (13) The above described compartments of the insulating liquid    covered with the above described resin film are made to be nearly    semispherical.-   (14) Active elements are arranged on the above described second    substrate and the display is switched over by means of the active    matrix driving.

According to the above described configurations, an electrophoreticdisplay can be provided which actualizes a uniform displaycharacteristic over the display surface.

Incidentally, the above described electrophoretic display can bemanufactured at least on the basis of the following steps of: (i)providing liquid-repellency parts on the surface of the first substrateor the second substrate, (ii) forming repellency-lowered parts byirradiating light onto the parts where the insulating liquid is to beprovided so as for the liquid repellency of the parts to be lowered, and(iii) providing the insulating liquid to the repellency-lowered partsformed by the above described light irradiation.

Other representative steps of manufacturing the electrophoretic displayof the present invention are detailed as follows.

(a) The above described steps (i) and (ii) are respectively;

(i) the step in which a layer to be used in the above step (ii) forabsorbing the light of 250 nm or longer in wavelength to lower theliquid repellency is provided on the surfaces of the first substrate andthe second substrate, on which layer another layer formed of anamorphous fluoro-containing polymer is provided, and

(ii) the step in which the light of 250 nm or longer in wavelength isirradiated onto the parts dividing the insulating liquid intocompartments and the liquid repellency of the light irradiated parts islowered.

(b) The above described step (iii) is a step in which the abovedescribed insulating liquid is sealed by vacuum evacuating the spaceformed with a predetermined gap between the above described firstsubstrate and the above described second substrate or by pressurizingthe insulating liquid.

(c) Alternatively, the above described step (iii) is a step in which theabove described insulating liquid is made to adhere by rolling a rolleronto which a prescribed thickness of the insulating liquid is adheredbeforehand, on the above described substrate.

(d) Alternatively, the above described step (iii) is a step in which theabove described insulating liquid is made to adhere by soaking thesurfaces of the above described substrates in the insulating liquidstored in a vessel.

(e) Alternatively, the above described step (iii) is a step in which theabove described insulating liquid is made to adhere by flying thedroplets of the insulating liquid by means of inkjetting.

(f) In the above steps (a) to (e), at least used are:

(1) the step in which added is a resin to be used in the following step(2) that is cured by light irradiation or by heating, and

(2) the step in which the resin is cured on the above described surfaceof the compartments of the insulating liquid by means of lightirradiation or heating, and accordingly the above described compartmentsof the insulating liquid are covered by the resin.

The use of the manufacturing methods described above permits providingan electrophoretic display in which a uniform display characteristic isactualized in the display surface, as above described in the above (1)to (14).

Other objects, features and advantages of the invention will becomeapparent from the following description of the embodiments of theinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A, 1B and 1C are schematic sectional view illustrating Example 1of the electrophoretic display of the present invention;

FIG. 2 is a schematic sectional view, similar to FIG. 1, illustratingExample 2 of the electrophoretic display of the present invention;

FIG. 3 is a schematic sectional view, similar to FIG. 1, illustratingExample 3 of the electrophoretic display of the present invention;

FIG. 4 is a schematic sectional view, similar to FIG. 1, illustratingExample 4 of the electrophoretic display of the present invention;

FIG. 5 is an oblique perspective view schematically illustrating a partof the display area of Example 7 of the electrophoretic display of thepresent invention;

FIG. 6 is a schematic sectional view, similar to FIG. 1, illustratingExample 9 of the electrophoretic display of the present invention;

FIG. 7 is a schematic sectional view, similar to FIG. 1, illustratingExample 10 of the electrophoretic display of the present invention;

FIG. 8 is a schematic sectional view, similar to FIG. 1, illustratingExample 11 of the electrophoretic display of the present invention;

FIG. 9 is a schematic sectional view, similar to FIG. 1, illustratingExample 12 of the electrophoretic display of the present invention;

FIG. 10 is a schematic sectional view, similar to FIG. 1, illustratingExample 13 of the electrophoretic display of the present invention;

FIG. 11 is a schematic sectional view, similar to FIG. 1, illustratingExample 14 of the electrophoretic display of the present invention;

FIG. 12 is a schematic sectional view, similar to FIG. 1, illustratingExample 15 of the electrophoretic display of the present invention;

FIG. 13 is a schematic sectional view, similar to FIG. 1, illustratingExample 16 of the electrophoretic display of the present invention;

FIG. 14 is a schematic sectional view, similar to FIG. 1, illustratingExample 17 of the electrophoretic display of the present invention;

FIG. 15 is a schematic sectional view, similar to FIG. 1, illustratingExample 18 of the electrophoretic display of the present invention;

FIG. 16 is a block diagram illustrating an example of the drivingcircuit of the electrophoretic display of the present invention;

FIG. 17 is a schematic view illustrating the structure of the secondsubstrate in FIG. 16 as viewed from the image surface;

FIG. 18 is a schematic sectional view along the line segment A-A′ shownin FIG. 17;

FIGS. 19A, 18B, 19C and 19D are schematic view illustrating themanufacturing steps of the electrophoretic display of the presentinvention;

FIGS. 20A, 20B and 20C are schematic view illustrating the step forproviding an insulating liquid to the repellency-lowered parts of theelectrophoretic display of the present invention in a manufacturingmethod other than that illustrated in FIG. 19;

FIGS. 21A, 21B and 21C are schematic view illustrating another exampleof other manufacturing steps of the electrophoretic display of thepresent invention;

FIGS. 22A, 22B and 22C are schematic view illustrating yet othermanufacturing steps of the electrophoretic display of the presentinvention;

FIGS. 23A, 23B and 23C are schematic view illustrating further yet othermanufacturing steps of the electrophoretic display of the presentinvention; and

FIGS. 24A and 24B are schematic view illustrating further yet othersteps in the manufacturing steps of the electrophoretic display of thepresent invention.

DESCRIPTION OF SYMBOLS

1: First substrate, 2: Second substrate, 3: First electrode, 4: Secondelectrode, 5: Insulating liquid, 6: Charged particle, 7: Insulatinglayer, 8: Liquid-repellency part, 9: Repellency-lowered part, 10:Electric circuit, 11: Post, 12: Resin film, 13: Resin, 14: Conductiveresin, 15: Resin, 16: Sealing opening, 17: Gas charging opening, 18:Roller, 19: Inkjet device, 20: Pixel, 21: Thin film transistor, 22:Drain wire, 23: Gate wire, 24: Drain driver, 25: Gate driver, 26: Bank,27: Photomask, 28: UV light, 31: Gate electrode, 32: Gate insulatingfilm, 33: Semiconductor layer, 34, 35: Contact layer, 36: Drainelectrode, 37: Source electrode

DETAILED DESCRIPTION OF THE INVENTION

Now, detailed description will be made below on the embodiment of theelectrophoretic display of the present invention with reference to theaccompanying drawings.

EXAMPLE 1

FIG. 1 is a view illustrating the first example of the electrophoreticdisplay of the present invention; FIG. 1A is a sectional view of thepart around a pixel, FIGS. 1B and C are the views illustrating theoperation of FIG. 1A. The range P shown in FIG. 1A corresponds to onepixel of the electrophoretic display. As FIG. 1A shows, theelectrophoretic display of the present invention comprises a firstsubstrate 1 and a second substrate 2 both arranged with an appropriategap therebetween, and a transparent insulating liquid 5 provided in thegap in which liquid colored charged particles 6 are dispersed. The firstsubstrate 1 is transparent and a first electrode 3 and a secondelectrode 4 are arranged on the second substrate 2, the area of thefirst electrode 3 is smaller than the area of the second electrode 4,and these two electrodes are separated with an insulating layer 7. Anelectric circuit 10 is connected to the first electrode 3 and the secondelectrode 4 with a polarity shown in the figure. The display has apartition wall 1A between adjacent pixels. In FIG. 1, the partition wall1A is made of a gas such as air, an inert gas or the like.

When a voltage is applied between the first electrode 3 and the secondelectrode 4 by the electric circuit 10, an electric filed is generatedbetween the two electrodes, and the charged particles 6 move either fromabove the first electrode 3 to above the second electrode 4 or fromabove the second electrode 4 to above the first electrode 3. When thecharged particles 6 are positively charged, as FIG. 1B shows, if thepotential of the first electrode 3 is made lower than that of the secondelectrode 4 by means of the electric circuit 10, the charged particles 6gather above the first electrode 3 smaller in area. In this case, whenviewed from the first substrate 1, the electrophoretic display exhibitseither the color of the second electrode 4 or the color of theinsulating layer 7.

On the other hand, as FIG. 1C shows, if a voltage is applied by means ofthe electric circuit 10 so as for the potential of the first electrode 3to be made higher than that of the second electrode 4, the chargedparticles 6 spread above the second electrode 4 larger in area. In thiscase, when viewed from the first substrate 1, the electrophoreticdisplay exhibits the color of the charged particles. For example, if thecolor of the charged particles 6 is black, the insulating layer 7 istransparent, and the second electrode 4 is high in reflectivity over thewhole visible light region, white display is effected in the case ofFIG. 1B while black display is effected in the case of FIG. 1C. In thisconnection, if only the color and brightness of the charged particles 6and those of the second electrode 4 can be observed with a sufficientcontrast, the respective colors may take any combinations.

Although for the first electrode 3, an electrode having arbitraryreflection characteristics may be used, a black or brown electrode ispreferable because the reflected light amount from the surface of suchan electrode is small to raise the contrast ratio. Additionally, in thecase where the second electrode 4 is used as a reflector, the luminanceof the display can be raised by appropriately nodularizing the surfaceof the second electrode 4 so that the light incident from thesurroundings is made to be reflected effectively along the directionnormal to the front surface of the display. Yet additionally, an effectequivalent to the effect which would be obtained by coloring the secondelectrode 4 can be obtained by making the reflection characteristics inthe visible light region of the second electrode 4 have wavelengthdispersion and by making the transmittance in the visible light regionof the insulating layer 7 have wavelength dispersion, instead ofcoloring the second electrode 4.

Furthermore, a full color electrophoretic display can be obtained asfollows: the present example is used as one pixel (color subpixel) andthe individual pixels are respectively provided with the secondelectrodes 4 mainly reflecting the lights in the red, green and bluewavelength regions, with the insulating layers 7 mainly transmitting thelights in the red, green and blue wavelength regions, or with the colorfilters (not shown in the figure) arranged on the first substrate andtransmitting the lights in the red, green and blue wavelength regions;black charged particles 6 are used; and voltages are applied to thesepixels independently.

Additionally, by arranging an insulating layer 7 between the firstelectrode 3 and the insulating liquid 5 and between the second electrode4 and the insulating liquid 5, the electrochemical reactions expected tooccur between the first electrode 3 and the insulating liquid 5 andbetween the second electrode 4 and the insulating liquid 5 can beprevented; however, the insulating layer 7 is necessary or unnecessarydepending on the combination of the two electrodes and the insulatingliquid 5.

EXAMPLE 2

FIG. 2 is a schematic sectional view, similar to FIG. 1, illustratingExample 2 of the electrophoretic display of the present invention. Inthe present example, as FIG. 2 shows, the first electrode 3 is arrangedon the first substrate 1, while in Example 1 the first electrode 3 isarranged on the second substrate. Even this configuration of the presentexample can effect a display similarly to the above described example.

EXAMPLE 3

FIG. 3 is a sectional view, similar to FIG. 1, illustrating Example 3 ofthe electrophoretic display of the present invention. In the presentexample, the first electrode 3 is commonized on the first substrate 1and a colored insulating liquid is used, while the first electrode 3 isarranged on the second substrate in Example 1. In the configuration ofthe present example, owing to the contrasting combination of the colorsof the colored insulating liquid 5 and the colored charged particles 6,the color of the particles is displayed when the charged particles 6spread over the first electrode 3, while the color of the coloredinsulating liquid 5 is displayed when the charged particles 6 spreadover the second electrode 4.

Additionally, the second substrate 2 and the second electrode 4 in eachof the electrophoretic displays of the above described examples can bemade transparent and these electrophoretic displays thus modified can beused as transmission type electrophoretic displays.

In the electrophoretic displays of Examples 1 to 3 of the presentinvention described above with reference to the above FIGS. 1 to 3, theliquid-repellency parts 8 having the repellency against the insulatingliquid 5 and the repellency-lowered parts 9 having the wettability tothe insulating liquid 5 are provided on the surface of the firstsubstrate 1 and the surface of the second substrate 2. As FIGS. 1 to 3show, the repellency-lowered parts 9 are arranged on parts of thesubstrate surface to be pixels and the liquid-repellency parts 8 arearranged on the boundary parts between the pixels; accordingly, theinsulating liquid 5 provided on each of the repellency-lowered parts 9remains in the part concerned, but never moves over the adjacentliquid-repellency parts 8. More specifically, even with such a simplestructure in which the partition walls 1A are formed of a gas so that nosubstantial walls are present, an electrophoretic display can beactualized in which the insulating liquid 5 is divided into compartmentsof the insulating liquid 5 each corresponding to one pixel.

The liquid-repellent parts 8 and repellency-lowered parts 9 referred tohere respectively refer to the parts having relatively high contactangles and the parts having relatively low contact angles to theinsulating liquid 5; no absolute values of the contact angles arespecified. Additionally, in Examples 1 to 3 of the present invention,the pattern shapes of the liquid-repellency parts 8 andrepellency-lowered parts 9 arranged on the first substrate 1 and thepattern shapes of the same arranged on the second substrate 2 are madeto coincide with each other; the insulating liquid 5 is provided betweenthe pairs of the opposing repellency-lowered parts 9 on both substrates,resulting in an effect that the division of the insulating liquid 5 intocompartments can be made more firmly.

EXAMPLE 4

FIG. 4 is a schematic sectional view, similar to FIG. 1, illustratingExample 4 of the electrophoretic display of the present invention. Inthe present example, the whole surface of the first substrate 1 is madeto be a liquid-repellency part 8, while liquid-repellency parts 8 andrepellency-lowered parts 9 are arranged on the surface of the secondsubstrate 2. Adoption of this configuration provides the effect that theinsulating liquid 5 is divided into compartments with the aid of theliquid-repellency parts 8 and the repellency-lowered parts 9 on thesecond substrate 2, and the contact of the adjacent compartments of theinsulating liquid 5 through the intermediary of the first substrate 1 isprevented. Furthermore, the adoption of the same configuration permitsomitting the process for patterning the liquid-repellency parts 8 andthe repellency-lowered parts 9 on the first substrate 1. On thecontrary, the same effect can be obtained by patterning theliquid-repellency parts 8 and the repellency-lowered parts 9 on thefirst substrate 1 and arranging only the liquid-repellency part 8 on thesecond substrate 2 (not shown in the figure).

EXAMPLE 5

In the electrophoretic display of the present example, theliquid-repellency parts 8 and repellency-lowered parts 9 are arrangedrespectively for the groups each consisting of a plurality of pixels,although in Examples 1 to 4 the insulating liquid 5 is divided intocompartments each allotted to one pixel. This configuration permitsactualizing an electrophoretic display in which the insulating liquid 5is divided into compartments each allotted to a group of a plurality ofpixels, with a simple structure without partition walls (not illustratedwith a figure). This configuration yields an effect that the productionefficiency is improved because the area of one of the compartmentsgenerated by equal division becomes large.

EXAMPLE 6

In the electrophoretic display of the present example, the insulatingliquid 5 is dropped onto the flat repellency-lowered part 9 shown inExamples 1 to 4 and the relevant contact angle is measured, and thesurface of the repellency-lowered parts 9 are nodularized in the casewhere the measured contact angle is smaller than 90 degrees (notillustrated with a figure). The nodularized shape of therepellency-lowered parts 9 leads to an effect that the contact angle ofthe insulating liquid 5 in relation to the repellency-lowered parts 9 islowered (the wettability is increased), and the division intocompartments can be made more firmly. The above mentioned nodularizedshape may be derived from the nodularized shape of the material itselfforming the repellency-lowered parts 9, and alternatively, if the secondelectrode 4 is used as a reflector having a nodularized shape, thisnodularized shape can also be utilized.

EXAMPLE 7

FIG. 5 is an oblique perspective view schematically illustrating a partof the display area of Example 7 of the electrophoretic display of thepresent invention. In the electrophoretic display of the presentexample, for the purpose of maintaining at a predetermined value the gapbetween the first substrate 1 and the second substrate 2, posts 11 arearranged as spaces on the liquid-repellency parts 8 in the constitutionof the electrophoretic display in Example 3. The posts 11 are arrangedon the mutual boundary portions between the compartments of theinsulating liquid. The arrangement of the posts 11 on theliquid-repellency parts 8 preferably permits maintaining thepredetermined gap without reducing the opening ratio (the area of therepellency-lowered parts 9). Furthermore, by providing the surface ofthe posts 11 with the repellency against the insulating liquid 5, themutual contact between the adjacent compartments of the insulatingliquid 5 through the intermediary of surface of the posts 11 is limitedand accordingly the division into the compartments can be made morefirm. Additionally, by making the color of the posts 11 nearly black,undesired reflected light and transmitted light can be reduced inintensity so that an electrophoretic display having a high contrast canbe obtained.

In FIG. 5, the posts 11 are arranged on the liquid-repellency partscorresponding to the four corners of each repellency-lowered part 9;however, the number of ports to be arranged and the arrangementlocations are not limited to those illustrated in FIG. 5. Although inFIG. 5 the same pattern shapes of the liquid-repellency parts 8 and therepellency-lowered parts 9 are shown on the first substrate 1 and thesecond substrate 2, a similar effect can be obtained when the wholesurface of one of these substrate is made to be a liquid-repellencypart.

EXAMPLE 8

In the present example, beads are used as spacer members (notillustrated with a figure) in place of the above described posts 11 tomaintain at a predetermined value the gap between the first substrate 1and the second substrate 2 in the example described with reference toFIG. 5. The beads are arranged randomly between the two substrates, sothat the beads are sometimes arranged between the compartments, eachcorresponding to one of the abutting pixels, of the insulating liquid;thus, by making the surface of the beads have the liquid repellency, themutual contact between the adjacent compartments of the insulatingliquid through the intermediary of the surface of the beads is limited,and hence the division into the compartments can be made more firm.Additionally, there is an effect that the liquid repellency imparted tothe beads makes the beads stably stay in the locations small in the areaof contact with the insulating liquid so as for the beads to stay in theliquid-repellency parts so that the reduction of the opening ratio canbe avoided. Additionally, by making the color of the beads nearly black,similarly to the case where the above described posts are made black,undesired reflected light and transmitted light can be reduced inintensity so that an electrophoretic display having a high contrast canbe obtained.

EXAMPLE 9

FIG. 6 is a schematic sectional view, similar to FIG. 1, illustratingExample 9 of the electrophoretic display of the present invention. Inthe electrophoretic display of the present example, banks 26 more convexthan the surroundings thereof are arranged in the boundary parts betweenthe compartments of the insulating liquid 5. Such an arrangement of thebanks 26 limits the mutual contact between the adjacent compartments ofthe insulating liquid 5 each corresponding to one of the pixels so thatthe division into the compartments can be made more firm. Additionally,the just mentioned arrangement permits preventing an effect that theinsulating liquid 5 adhered to the liquid-repellency parts 9 flows overthe banks 26 into either of the adjacent compartments of the insulatingliquid 5 so that eventually part of the insulating liquid 5 remains inthe liquid-repellency parts 8. Additionally, although in FIG. 6 thebanks 26 are arranged exclusively in the liquid-repellency parts 8 ofthe second substrate 2, the banks 26 may be arranged on the firstsubstrate 1 or on both substrates (not illustrated with a figure).

EXAMPLE 10

FIG. 7 is a schematic sectional view, similar to FIG. 1, illustratingExample 10 of the electrophoretic display of the present invention. Inthe present example, the surface of each of the compartments of theinsulating liquid 5 in the above described examples (Examples 1 to 9) iscovered with a resin film 12. The covering of the compartments of theinsulating liquid 5 with a resin film 12 in the present example preventsthe mutual contact of the adjacent compartments of the insulating liquideven when the substrates are compressed from the outside so as for thegap between both substrates to be narrower, and hence firm compartmentstructure can be actualized. Additionally, although in FIG. 7 theliquid-repellency parts 8 and the repellency-lowered parts 9 arepatterned on the second substrate 2, an electrophoretic display havingan effect similar to the above described can be obtained by patterningthe liquid-repellency parts 8 and the repellency-lowered parts 9 on thefirst substrate 1 (not illustrated with a figure) in contrast to theabove described structure.

EXAMPLE 11

FIG. 8 is a schematic sectional view, similar to FIG. 1, illustratingExample 11 of the electrophoretic display of the present invention. Inthe present example, resin 13 is arranged in place of the partitionwalls 1A formed of air, an inert gas or the like in the exampleillustrated in FIG. 7. The arrangement of the resin 13 permitsmaintaining more firmly the gap between the first substrate 1 and thesecond substrate 2, and yields an effect that the mutual contact of theadjacent compartments of the insulating liquid 5 can be prevented evenwhen both substrates are compressed from the outside, and hence morefirm separation into compartments is actualized. Incidentally, by makingthe resin 13 nearly black, an effect occurs that undesired reflectedlight and transmitted light from the resin 13 can be reduced inintensity, and accordingly an electrophoretic display having a highcontrast can be obtained.

EXAMPLE 12

FIG. 9 is a schematic sectional view, similar to FIG. 1, illustratingExample 12 of the electrophoretic display of the present invention. Inthe present example, partition walls of a conductive resin 14 arearranged respectively in the gaps between the compartments of theinsulating liquid 5 each covered with a resin film 12 in the exampleillustrated in FIG. 8, and the partition walls of a conductive resin 14are made to respectively be the common electrodes of the pixels.Incidentally, the conductive resin 14 can be made to double as theelectrodes corresponding to the first electrodes 3. Making theconductive resin 14 double as the first electrodes 3, in anelectrophoretic display using a transparent insulating liquid 5, givesrise to an effect of increasing the opening ratio and hence can lead toactualization of an electrophoretic display having a bright displayimage. Such doubling of the conductive resin partition walls as thefirst electrodes 3 also gives rise to an effect that a step for formingthe first electrodes 3, as in the above described examples, above thesecond electrodes 4, or on the first substrate 1 or the second substrate2, can be omitted and the structure of the display can be simplified.

EXAMPLE 13

FIG. 10 is a schematic sectional view, similar to FIG. 1, illustratingExample 13 of the electrophoretic display of the present invention. Inthe present example, a layer of the conductive resin 14 is arranged inthe gap between the group of the gaps (partition walls) associated withthe compartments of the colored insulating liquid 5, each covered with aresin film 12, and the first substrate 3. The part thus formed of theconductive resin 14 is made to be a common electrode to double as thefirst electrode 3. The configuration of the present example gives riseto an effect that the step for forming the first electrodes 3 on thefirst substrate 1 can be omitted and the structure of the display can besimplified.

EXAMPLE 14

FIG. 11 is a schematic sectional view, similar to FIG. 1, illustratingExample 14 of the electrophoretic display of the present invention. Thepresent example has the configuration similar to that in FIG. 10, inwhich, similarly to the configurations shown in FIGS. 8 to 10, a layerof the conductive resin 14 is arranged between the gaps (partitionwalls) associated with the compartments of the transparent insulatingliquid 5, each covered with a resin film 12 and the gap between thecompartments of the insulating liquid and the first substrate 3, andmoreover, the size of the second electrode 4 arranged on the secondsubstrate 2 is made small. According to the present example, in additionto an effect similar to the effect obtained in Example 13, thetransmittance can be improved owing to the small area of the secondelectrode 4.

EXAMPLE 15

FIG. 12 is a schematic sectional view, similar to FIG. 1, illustratingExample 15 of the electrophoretic display of the present invention. Inthe present example, the compartments of the insulating liquid 5 eachcovered with a resin film 12 are made nearly semispherical and a secondelectrode 4 is arranged on the central part of each of thesesemispheres, and a conductive resin 14 fills the partition wall parts(gap parts) between the adjacent compartments of the insulating liquid 5and the gap between the first substrate 1 and these compartments. Thepart formed of the conductive resin 14 may double as the first electrode3 as the common electrode for the individual pixels. There occurs aneffect that this configuration uniformizes the electric fielddistribution between the first electrode 3 (the common electrode: theconductive resin part 14 and the second electrode 4 so that the chargedparticles spread uniformly all over the surface of the first electrode3. Additionally, when the refractive index of the insulating liquid 5 islower than the refractive indexes of the above described resins 12 and14, the semispherical structure has an effect of a convex lens toenhance the reflectivity for white display so that an electrophoreticdisplay higher in contrast ratio can be obtained.

EXAMPLE 16

FIG. 13 is a schematic sectional view, similar to FIG. 1, illustratingExample 16 of the electrophoretic display of the present invention. Thepresent example has a configuration in which the first substrate 1 ineach of the above described examples is omitted, and a conductive resin14 fills the partition wall parts (gap parts) associated with thecompartments of the transparent insulating liquid 5 each covered with aresin film 12, the conductive resin 14 doubles as the first electrode 3,and the surface of the conductive resin part is covered with aninsulating film 15. The use of the insulating film 15 in place of thefirst substrate 1 permits actualizing an electrophoretic display lightin weight, low in profile, and flexible.

EXAMPLE 17

FIG. 14 is a schematic sectional view, similar to FIG. 1, illustratingExample 17 of the electrophoretic display of the present invention. Thepresent example has a structure in which, similarly to Example 15, thesurface of the part formed of the conductive resin 14, replacing thefirst substrate 1 and doubling as the first electrode 3, is covered withan insulating film 15, and the size of the second electrode 4 arrangedon the second substrate 2 is made small. According to the presentexample, in addition to an effect similar to the effect obtained inExample 15, the transmittance can be improved owing to the small area ofthe second electrode 4 so that an electrophoretic display having abright display image can be actualized.

EXAMPLE 18

FIG. 15 is a schematic sectional view, similar to FIG. 1, illustratingExample 18 of the electrophoretic display of the present invention. Thepresent example has a configuration in which, similarly to the exampleillustrated in FIG. 12, the shape of the compartments of the insulatingliquid 5 is made nearly semispherical, a second electrode 4 is arrangedon the central part of each of the semispheres, and a conductive resin14 fills the partition wall parts (gap parts) between the adjacentcompartments of the insulating liquid 5 and the gap between the firstsubstrate 1 and these compartments. The part formed of the conductiveresin 14 may double as the first electrode 3 as the common electrode forthe individual pixels. Additionally, the first substrate 1 in FIG. 12 isomitted and the surface of the part formed of the conductive resin 14 iscovered with an insulating film 15. The configuration of the presentexample permits achieving an effect obtained with a combination of theexample associated with FIG. 12 and the example associated with FIG. 14.

An arbitrary image can be displayed by arranging in a matrix form thepixels of any one of the above described electrophoretic displays in theexamples of the present invention, and by voltage controlling each ofthe pixels separately. As the driving scheme involved in the control,either an active driving or a passive driving can be adopted; inconsideration of the effect of cross-talk possible in a case where thenumber of the pixels is large, an active driving is preferable. Now,description will be made below on some examples each adopting an activedriving.

FIG. 16 is a block diagram illustrating an example of the drivingcircuit of the electrophoretic display of the present invention.Reference numeral 20 denotes a pixel, one of the first electrode and thesecond electrode of each pixel 20 is connected to a thin film transistor21, a drain wire 22 and a gate wire 23 for the purpose of applyingvoltage, and the other electrode is connected and commonized so as tohave an identical voltage between the adjacent pixels. The voltageapplied between the first electrode and the second electrode of eachpixel 20 is controlled by a driver 24 for the drain wiring 22 and adriver 25 for the gate wiring.

FIG. 17 is a schematic view illustrating the structure of the secondsubstrate in FIG. 16 as viewed from the image surface. In FIG. 17, thethin film transistors 21, the drain wires 22 and the gate wires 23 areall arranged on the second substrate, and the liquid-repellency parts 8are arranged at the locations illustrated in the figure. The abovedescribed first electrode 3 is arranged on the first electrode 1 notshown in the FIG. 17, and the adjacent pixels are commonly connected(not shown in the figure). The above described second electrodes 4 areeach connected with one of the thin transistors 21. Then, descriptionwill be made with reference to a sectional view including the thin filmtransistors 21 in combination with the structures of the above describedexamples.

FIG. 18 is a schematic sectional view along the line segment A-A′ shownin FIG. 17, illustrating the portion involving one thin film transistor.FIG. 18 shows an electrophoretic display in which the pixel is the onehaving the structure of Example 1. The reference numerals respectivelycorrespond to the reference numerals allotted to the parts having thesame functions in the above described examples. In FIG. 18, the secondelectrode 4 is connected to the source electrode 37 of the thin filmtransistor 21 through the intermediary of a through hole. The thin filmtransistor 21 comprises a gate electrode 31, an insulating film 32, asemiconductor layer 33, a contact layer 34 and 35, a drain electrode 36and a source electrode 37. The first electrode 3 is connected betweenthe adjacent pixels and is made to be a common electrode. Thus, activematrix driving is made possible.

Now, description will be made below on a manufacturing method of theelectrophoretic of the present invention, in particular, on the step forforming the liquid-repellency parts and the repellency-lowered parts onthe first substrate and the second substrate and on the step forproviding the insulating liquid to the repellency-lowered parts on bothsubstrates.

FIG. 19 is a schematic view illustrating the manufacturing steps of theelectrophoretic display of the present invention, and corresponds to themanufacture of the above described electrophoretic display of Example 1.In a step shown in FIG. 19A for arranging the liquid-repellency parts onthe second substrate, a liquid-repellency treatment is made all over thesurface of the second substrate 2 to form the liquid-repellency parts 8all over the surface of the substrate. The liquid-repellency parts 8 areformed by the liquid-repellency liquid coating methods based on theliquid phase processes including the spin coat method, the dip coatmethod and the like, or by the vapor phase processes including theplasma processing in the atmosphere of the liquid-repellency gas and thelike. FIG. 19B shows a next step in which light irradiation is made ontothe portions on which the insulating liquid is to be provided, and thusthe repellency-lowered portions are formed by lowering the liquidrepellency of the light irradiated parts. In this step, the light 16 isirradiated through a photomask 27, and the light irradiated parts aremade to lose liquid repellency and to be transformed into therepellency-lowered parts 9. In this connection, the liquid repellencymay be incompletely eliminated so as for the repellent liquid to bemodified so that the liquid repellency is lowered and the irradiatedparts become the repellency-lowered parts.

Then, a structure as shown in FIG. 19C is obtained through the step forproviding the above described insulating liquid 5 to therepellency-lowered parts 9 formed by the above described lightirradiation. Thereafter, an electrophoretic display having a structureshown in FIG. 19D is obtained by laminating, on the above describedinsulating liquid, the first substrate 1 having the sameliquid-repellency parts 8 and the same repellency-lowered parts 9 formedthereon. Incidentally, in the step for providing the insulating liquid 5to the repellency-lowered parts 9, the insulating liquid 5 provided tothe liquid-repellent parts 8 is attracted to the repellency-loweredparts 9 so that it is possible to provide the insulating liquid 5exclusively to the repellency-lowered parts 9; thus, if therepellency-lowered parts 9 are formed in a grid pattern, it is possibleto simply manufacture an electrophoretic display in which the insulatingliquid 5 is divided into compartments without using partition walls.

Additionally, in the above described step for providing aliquid-repellency layer, at the beginning as a base for the layer, alayer for absorbing the light irradiated for the purpose of lowering theliquid repellency may be formed on the substrate, and aliquid-repellency layer may be provided thereon (not illustrated with afigure). Such a preformation of the light absorbing layer makes itpossible to form the patterns of the liquid-repellency parts and therepellency-lowered parts by eliminating or modifying theliquid-repellency layer with the aid of the heat generated in theirradiated parts when the light of 250 nm or longer in wavelength (forexample visible light) is irradiated. Accordingly, a process in vacuuminvolved in the ultraviolet light irradiation can be eliminated andsimpler steps can manufacture an electrophoretic display.

FIG. 20 is a schematic view illustrating the step for providing aninsulating liquid to the repellency-lowered parts of the electrophoreticdisplay of the present invention in a manufacturing method other thanthat illustrated in FIG. 19. As FIG. 20 shows, the first substrate 1 andthe second substrate 2 beforehand provided with the liquid-repellencyparts 8 and the repellency-lowered parts 9 are laminated with apredetermined gap and a sealing opening 16 arranged in the gap, then theabove described sealing opening 16 is submerged into the insulatingliquid 5 (FIG. 20A), and thus, the insulating liquid 5 is sealed betweenthe two substrates by evacuating to a vacuum the space between the twosubstrates (FIG. 20B). Thereafter, the sealing opening 16 is separatedfrom the insulating liquid 5, and consequently the unnecessaryinsulating liquid provided to the liquid-repellency parts 8 isdischarged from the sealing opening 16 or the gas discharge opening 17.In this way, an electrophoretic display can be manufactured in which theinsulating liquid is simply divided into compartments with the aid of agas as the partition walls, without using as the partition walls suchresins as described in the examples with reference to FIG. 8 and thelike (FIG. 20C). In this connection, evacuation to a vacuum may be madefrom the gas discharge opening 17 to accelerate the discharge of theunnecessary insulating liquid. Alternatively, the insulating liquid maybe sealed between the two substrates by pressurizing the insulatingliquid 5, instead of the evacuation to a vacuum.

FIG. 21 is a schematic view illustrating another example of othermanufacturing steps of the electrophoretic display of the presentinvention. The manufacturing steps also correspond to the manufacture ofthe electrophoretic display of Example 1. In the step for providing theinsulating liquid 5 to the repellency-lowered parts 9, as FIG. 21 shows,a roller 18 with the insulating liquid 5 adhering thereto in apredetermined thickness is rolled on the first substrate 1 beforehandprovided with the liquid-repellency parts 8 and the repellency-loweredparts 9 on the surface thereof (FIG. 21A) in such a way that theinsulating liquid 5 is provided exclusively to the repellency-loweredparts 8 of the above described substrate (FIG. 21B). Then, the firstsubstrate 1 is laminated with a predetermined gap to the secondsubstrate 2 having the same liquid-repellency parts 8 and the samerepellency-lowered parts 9 on the surface thereof. In this way, asdescribed with reference to FIGS. 10 to 20, it becomes possible-tosimply divide the insulating liquid into compartments with the aid ofgas partition walls (FIG. 21C). In this case, by making the thickness ofthe insulating liquid adhering to the roller 19 agree with the gap withwhich the first substrate 1 and the second substrate 2 are laminated, orby making the thickness concerned thick so as for the adjacentcompartments of the insulating liquid not to contact each other, theinsulating liquid 5 can be made to contact the first substrate 1 and thesecond substrate 2 without failure. Accordingly, it is possible todivide the insulating liquid into compartments with the aid of gaspartition walls. Incidentally, in this case, the insulating liquid 5 isprovided to the first substrate 1, but the insulating liquid 5 may alsobe provided to the second substrate.

FIG. 22 is a schematic view illustrating yet other manufacturing stepsof the electrophoretic display of the present invention. Themanufacturing steps also correspond to the manufacture of theelectrophoretic display of Example 1. At the beginning, the firstsubstrate 1 beforehand provided with the liquid-repellency parts 8 andthe repellency-lowered parts 9 on the surface thereof is soaked in theinsulating liquid 5 (FIG. 22A), then the first substrate 1 is taken outto arrange the insulating liquid 5 exclusively on the repellency-loweredparts 8 of the first substrate 1 (FIG. 22B). Then, the first substrate 1is laminated with a predetermined gap to the second substrate 2.Accordingly, the insulating liquid can be simply divided intocompartments with the aid of gas partition walls (FIG. 22C). In thiscase, the adhesion amount of the insulating liquid 5 onto therepellency-lowered parts 9 of the first substrate 1 can be adjusted byvarying the surface tension and viscosity of the insulating liquid 5 andthe surface tension and viscosity of the repellency-lowered parts 9.Here, the insulating liquid 5 is provided to the first substrate 1, butthe insulating liquid 5 may also be provided to the second substrate 2.

FIG. 23 is a schematic view illustrating further yet other manufacturingsteps of the electrophoretic display of the present invention. Themanufacturing steps also correspond to the manufacture of theelectrophoretic display of Example 1. In FIG. 23, in the step forproviding the insulating liquid 5 to the repellency-lowered parts 9, anappropriate amount of the insulating liquid 5 is discharged by means ofan inkjet device 19 to the repellency-lowered parts 9 of the firstsubstrate 1 beforehand provided with the liquid-repellency parts 8 andthe repellency-lowered parts 9 on the surface thereof (FIG. 23A), andthus the insulating liquid 5 is provided exclusively to therepellency-lowered parts 9 of the substrate (FIG. 23B). Then, thesubstrate 1 thus processed is laminated with a predetermined gap to thesecond substrate 2 having the same liquid-repellency parts 8 and thesame repellency-lowered parts 9 on the surface thereof. Accordingly, theinsulating liquid can be simply divided into compartments without usingpartition walls (FIG. 23C). Here, the insulating liquid 5 is provided tothe first substrate 1, but the insulating liquid 5 may also be providedto the second substrate 2.

FIG. 24 is a schematic view illustrating further yet other steps in themanufacturing steps of the electrophoretic display of the presentinvention. The manufacturing steps also correspond to the manufacture ofthe electrophoretic display of Example 1. In the present example, in thestep for covering the circumference of the compartments of theinsulating liquid 5 with a resin film 12, a photocuring material to formthe resin film 12 is beforehand added to the insulating liquid 5, andthe insulating liquid 5 is provided exclusively to therepellency-lowered parts 9 of the first substrate 1 according to any oneof the steps described above with reference to FIGS. 19 to 23. As FIG.24A shows, under this condition, light 28 is irradiated through aphotomask 27 to the parts to be covered with the resin film 12, and thusthe resin film 12 is formed to cover the compartments of the insulatingliquid 5. Then, as FIG. 24B shows, the second substrate 2 is laminatedwith a predetermined gap to the first substrate 1 in which the surfaceof the compartments of the insulating liquid 5 is covered with the resinfilm 12. Accordingly, the insulating liquid can be simply divided intocompartments without using partition walls.

Incidentally, a photocuring material to form the resin film 12 may beadded by means of spraying after the insulating liquid 5 has beenprovided exclusively to the repellency-lowered parts 9 on the firstsubstrate 1 according to any one of the steps described above withreference to FIGS. 19 to 23. Additionally, by making the specificgravity of the material to form the resin film 12 smaller than thespecific gravity of the insulating liquid 5, the surface of thecompartments of the insulating liquid is covered with the material toform the resin film 12, and then the material is cured to from the resinfilm 12 so that the material to form the resin film 12 hardly remains inthe insulating liquid 5. Through these steps, an electrophoretic displaycan be manufactured in which the insulating liquid is firmly dividedinto compartments. Similarly, the resin film 12 may be formed bythermosetting after a thermosetting material to form the resin film 12has been added to the insulating liquid.

Examples of the materials for the substrate 1 in each of the abovedescribed examples of the present invention include glass substrates,quartz substrates, and various polymer substrates on which electrodesand the like are to be laminated, and it is preferable that thematerials concerned simultaneously have insulation characteristics, hightransmittance for the visible light region and high mechanicalstrengths. Examples of the second substrate 2 include glass substrates,quartz substrates, various polymer substrates, and metal substrates eachhaving an insulating layer on the surface thereof on which electrodesand the like are to be laminated, and it is preferable that thesubstrates simultaneously have insulation characteristics and highmechanical strengths.

For the first electrode 3, the following materials can be used:materials having high reflectivity in the visible light region such asaluminum, aluminum alloys, silver, silver alloys, gold, copper,platinum, chromium, nickel, molybdenum, tungsten, titanium and the like;transparent materials such as indium tin oxide and the like; and blackmaterials such as carbon, titanium carbide, chromium and silversubjected to surface oxidation treatment, and the like. Additionally,non-black electrodes can be used as the first electrode 3 throughadhering black materials onto these electrodes. It is preferable thatthese materials are highly conductive, and from the viewpoint of thecontrast ratio, it is preferable that these materials are black.Besides, it is preferable that these materials are high in transmittancewhen the first electrode 1 is formed as the common electrode on thefirst substrate.

For the second electrode 4, the following materials are preferable:materials having high reflectivity in the visible light region such asaluminum, aluminum alloys, silver, silver alloys, gold, copper,platinum, chromium, nickel, molybdenum, tungsten, titanium and the like;highly conductive materials such as transparent indium tin oxide and thelike; and black materials from the viewpoint of the contrast ratio.Additionally, materials high in reflectivity are preferable for thesecond electrode when the second electrode is used as the reflector of areflection type display, while materials high in transmittance arepreferable when the second electrode is used in a transmission typedisplay.

For the insulating liquid 5, transparent materials such as xylene,toluene, silicon oil, liquid paraffin, organic chlorides, varioushydrocarbons, various aromatic hydrocarbons and the like can be usedeach alone and in combinations thereof. Materials high in transmittanceare preferable from the viewpoint of the light utilization efficiency.As a colored insulating liquid, a transparent insulating liquid addedwith an appropriate amount of a dye can be used. From the viewpoint ofthe operation life, it is preferable that the insulating liquid has ahigh insulation degree so that no ions are generated when voltage isapplied, while from the viewpoint of the migration velocity, it ispreferable that the insulating liquid has a low viscosity. Additionally,from the viewpoint of dividing the insulating liquid into compartments,it is preferable that the insulating liquid has a large differencebetween the contact angle to the liquid-repellency parts 8 and thecontact angle to the repellency-lowered parts 9.

For the charged particles 6, various organic pigments and inorganicpigments can be used, and various colors can be selected depending onthe selected materials. As black pigments, for example, carbon black,graphite, black iron oxide, ivory black, chromium dioxide and the likecan be used each alone or in combinations thereof. As white pigments,for example, titanium dioxide, magnesium oxide, barium titanate and thelike can be used. Furthermore, it is preferable to use pigments forwhich the dispersion characteristics are improved by coating thesepigments with dispersants such as acrylic polymers and the like, and thezeta potential of the particles is enhanced with the aid of asurfactant, because the stability and response speed of the chargedparticles are improved.

For the insulating layer 7, acrylic photosensitive resins,nonphotosensitive resins and inorganic insulating layers can be used.The insulating layer can be colored with dyes and the like, and candisplay a color in contrast to the color of the charged particles. Forthe liquid-repellency parts 8, alkoxysilane compounds, fluoro-containingaminosilane compounds and the like can be used, and those materialswhich have large contact angles to the insulating liquid are preferable.For the repellency-lowered parts 9, hydroxy group, carboxylic acid groupand sulfonic acid group can be cited, and the materials each having ahigh transmittance and a small contact angle to the insulating liquidare preferable.

For the resin film 12, various types of resins including photocuringtype resins, thermosetting type resins, condensation-polymerizationcuring type resins and the like can be used; examples of the photocuringtype include acrylic acids having long chain alkyl groups or benzenerings, acrylates having long chain alkyl groups or benzene rings and thelike. Materials high in transmittance are preferable. Additionally,preferable are those materials which have the characteristics such thatthe materials are soluble in the insulating liquid 5, the specificgravities of the materials are largely different from the specificgravity of the insulating liquid 5 and the like, depending on the curingmethods involved.

For the resin 13, various types of resins can be used, and thermosettingand photocuring resins may be used to be cured after having beenprovided between the compartments of the insulating liquid.Additionally, as black resins, resins mixed with carbon black and blackpigments, and the like can be used. Materials low in viscosity arepreferable for the purpose of providing the materials between thecompartments of the insulating liquid. For the conductive resin 14, theresin 13 kneaded with metals, carbon and the like and the resin 13 withions driven thereinto can be used. Alternatively, sheet-like materialswith adhered transparent electrodes such as ITO and the like may beused. Resins high both in transmittance and in conductivity arepreferable. For the spacer members, various types of polymer beads,silica beads and fibers can be used; materials high in liquid repellencyor materials enhanced in liquid repellency through coating withliquid-repellency materials are preferable.

As described above, according to the present invention, anelectrophoretic display can be provided in which an insulating liquidcan be divided into compartments each corresponding to one pixel, on thebasis of a simple structure, with the aid of the liquid-repellency partsand the repellency-lowered parts on the surface of the substrates, andthe insulating liquid can be uniformly arranged in the respectivemicrospaces so that display characteristics uniform in the displaysurface are actualized.

It should be further understood by those skilled in the art thatalthough the foregoing description has been made on embodiments of theinvention, the invention is not limited thereto and various changes andmodifications may be made without departing from the spirit of theinvention and the scope of the appended claims.

1-8. (canceled)
 9. An electrophoretic display comprising a pair ofsubstrates arranged with a predetermined gap therebetween, an insulatingliquid provided in said gap, charged particles dispersed in saidinsulating liquid, and a first electrode arranged on one of the pair ofsubstrates and a second electrode arranged on another of the pair ofsubstrates, wherein: the display comprises liquid-repellency parts andrepellency-lowered parts on the surface of the pair of substrates, andsaid insulating liquid is arranged on the repellency-lowered parts. 10.The electrophoretic display according to claim 9, wherein the displayfurther comprises spacer members on said liquid-repellency parts. 11.The electrophoretic display according to claim 9, wherein an image isdisplayed by applying voltage to the first electrode and the secondelectrode.
 12. The electrophoretic display according to claim 9, whereinat least one of the insulating liquid or the charged particles iscolored.
 13. The electrophoretic display according to claim 9, whereinthe second electrodes have function of reflecting lights in red, greenand blue wavelength regions.
 14. The electrophoretic display accordingto claim 9, wherein the first substrate comprises an insulating layerwhich transmits lights in red, green and blue wavelength regions. 15.The electrophoretic display according to claim 9, which furthercomprises a color filter, the color filter being arranged on the firstsubstrate and the color filter transmitting lights in red, green andblue wavelength regions.
 16. An electrophoretic display comprising apair of substrates arranged with a predetermined gap therebetween, aninsulating liquid provided in said gap, charged particles dispersed insaid insulating liquid, and a first electrode and a second electrodearranged on one of the pair of substrates and a second electrodearranged on another of the pair of substrates, wherein: the displaycomprises liquid-repellency parts and repellency-lowered parts on thesurface of one of the pair of substrates, said insulating liquid isarranged on the repellency-lowered parts, and the insulating liquid iscovered with a resin film.
 17. The electrophoretic display according toclaim 16, wherein either of air, inert gas or a resin is filled on theliquid-repellency parts.
 18. The electrophoretic display according toclaim 16, wherein an image is displayed by applying voltage to the firstelectrode and the second electrode.
 19. The electrophoretic displayaccording to claim 16, wherein at least one of the insulating liquid orthe charged particles is colored.
 20. An electrophoretic displaycomprising a pair of substrates arranged with a predetermined gaptherebetween, an insulating liquid provided in said gap, chargedparticles dispersed in said insulating liquid, and an electrode arrangedon one of the pair of substrates, wherein: the display comprisesliquid-repellency parts and repellency-lowered parts on the surface ofthe pair of substrates, said insulating liquid is covered with a resinfilm, and a conductive resin is arranged on the liquid-repellency parts.21. The electrophoretic display according to claim 20, wherein an imageis displayed by applying voltage to the electrode and the conductiveresin.
 22. The electrophoretic display according to claim 20, whereinthe conductive resin is arranged between another of the pair ofsubstrates and the resin film.
 23. The electrophoretic display accordingto claim 20, wherein the compartments of the insulating liquid eachcovered with said resin film are nearly semispherical.
 24. Anelectrophoretic display comprising a substrate and an insulating filmarranged with a predetermined gap therebetween, an insulating liquidprovided in said gap, charged particles dispersed in said insulatingliquid, and an electrode arranged on the substrate, wherein: the displaycomprises liquid-repellency parts and repellency-lowered parts, saidinsulating liquid is covered with a resin film, and a conductive resinis arranged on the liquid-repellency parts.
 25. The electrophoreticdisplay according to claim 24, wherein the conductive resin is arrangedbetween the insulating film and the resin film.
 26. The electrophoreticdisplay according to claim 24, wherein the compartments of theinsulating liquid each covered with said resin film are nearlysemispherical.